Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 5,825	$ 7,197	$ 25,201	$ 8,791
Basic-weighted average shares outstanding (in shares)	28,124	27,924	28,096	27,915
Effect of dilutive potential securities (in shares)	964	259	776	209
Diluted- weighted average shares outstanding (in shares)	29,088	28,183	28,872	28,124
Basic (in dollars per share)	$ 0.21	$ 0.26	$ 0.90	$ 0.31
Diluted (in dollars per share)	$ 0.20	$ 0.26	$ 0.87	$ 0.31
Antidilutive securities excluded from computation of earnings per share (in shares)	0	1,300	600	1,200